Management options for corn nematodes (microscopic, thread-like round worms that are parasites on or in root systems) are limited, but the first seed treatment nematicide for corn was recently registered for use. A seed treatment nematicide can protect corn seeds from day one, promoting strong stands and emergence. Plus, seed treatments protect growers’ corn seed investments.

Some other management practices can suppress or limit the growth of corn nematode populations:

Crop rotation, although effectiveness depends on the nematodes species and availability of other host plants

Over the past few years (and days), atrazine, one of the most widely used herbicides in the U.S. and around the world, been called into question in the media.The thing is, since atrazine was first introduced 50 years ago, the EPA says that atrazine “is one of the most closely examined pesticides in the marketplace.”

As you may know, crop protection products are among the most heavily regulated and scrutinized products available. Every one sold or distributed in the United States undergoes a stringent safety review by the EPA. In fact, pesticides are subject to more safety testing than pharmaceuticals prior to human clinical trials.

Atrazine recently completed a rigorous, up-to-date safety evaluation by the EPA and was re-registered for use in agriculture.In 2006, the EPA looked at all of the triazine herbicides together — atrazine, simazine and propazine — and determined they pose "no harm that would result to the general U.S. population, infants, children or other major identifiable subgroups of consumers."

While it’s true that extremely low levels of atrazine are occasionally found in some community water systems, its’ time we get this issue into perspective.In 2008, none of the 122 community water systems monitored in 10 states where atrazine is used most exceeded the federal standards set for atrazine in drinking water or raw water. The federal lifetime drinking water standard for atrazine is set at 3 parts-per-billion — a level containing a 1,000-fold safety factor. Put another way, a 150-pound adult could drink 21,000 gallons of water containing 3 ppb of atrazine every day for 70 years and still not reach levels shown to have no effects in lab studies.Plus, the best management practices growers now use near waterways have done much to protect water quality over the last 15 years.

Don’t forget that many products we use all the time – like bleach, antibiotics and even hand cleaners – can be considered toxic.But used in the proper way, according to the label, they are very beneficial.The same can be said for a time-tested herbicide like atrazine.

Internet and mobile technology have changed the way growers get information like weather, commodities, parts, sales, scouting reports and more. A University of Illinois article notes that new media offer ways to get information to you, but has this technology also changed the way you interact?

“Social media” like this blog community, Facebook, Twitter and others are growing rapidly. So what does that mean for how you do business? Solve problems? Make friends? Research inputs? Make recommendations?

Are you “chatting” with others more than you (or your parents and landlords) did 10 or 15 years ago? For example, do you participate in Twitter’s weekly #agchat? Are you a fan of organizations like the National Corn Growers Association on Facebook? And how can industry add to those conversations?

CO2 assimilation is one part of the process of photosynthesis. Plants require water, light and carbon dioxide to produce energy during photosynthesis, and the more efficient a plant is at fixing carbon during the dark reaction of photosynthesis, the more efficient it is at producing energy.

Azoxystrobin is responsible for improving the assimilation of carbon dioxide (CO2), which enhances plant photosynthesis. Azoxystrobin essentially enhances the plant’s ability to produce energy for a crop. This means more efficient use of the sun’s energy, resulting in a healthier plant and higher yields.

This photo demonstrates that plants treated with fungicide remain green longer than do untreated plants. Treated plants are able to utilize the sun's energy in the process of photosynthesis longer and put more photoassimilants into corn development (greater yields).
Untreated Treated
Yield 160 bu/A Yield 190 bu/A

My team has been working to share useful information on www.FarmAssist.com, and we’ve made several updates recently.

Check out the Learning Modules, where you can learn about corn nematodes, early season weed control, potato seed treatment, and more. Plus, Certified Crop Advisors (CCAs) can earn Continuing Education Units (CEUs) through many of the modules there.

Changing production practices are escalating corn nematode populations. These microscopic, thread-like round worms are an increasingthreat to top-quality corn production.

Some plant parasitic nematodes are sensitive to soil disturbance, so the increase in no-till acres has created a more hospitable environment. Corn-on-corn production gives nematodes the resources to thrive year after year. And, switching to insect-resistant corn and pyrethroid insecticides has moved growers away from using organophosphate and carbamate insecticides, which provided some suppression of nematodes.

Corn nematodes have been found in every major corn-growing county in the U.S. These maps show the risk levels for nematode pressure in the Midwest and South.Root-knot Nematode Distribution in the U.S. (South)

Deciding on a fungicide that offers broad-spectrum disease control is vital. Foliar diseases can eat away at plant yield, with some capable of reducing yield up to 40 percent. This alarming statistic makes it vital to use a fungicide with broad-spectrum activity that ensures the crop is protected regardless of the fungal pathogens present in the field. Azoxystrobin is part of the strobilurin family, the only fungicide group that controls fungi in all four classes of fungi.

Often, disease control is considered a secondary concern to other pests, but the impact to your crop can be significant. For instance, although disease control has not historically been an area of great concern, gray leaf spot is a disease that can greatly impact profitability. According to The Ohio State University and Purdue University Extension partnership newsletter “Ag Answers”, gray leaf spot can cause up to a 50 percent yield loss in corn, depending on the level of disease present. Additional data from Iowa State University suggests even greater losses of up to 69 percent.

Many times, the onset of disease can occur before it is visible by the naked eye. Early infections can arise in the plant before a fungicide has been applied. Usually, disease does not present itself until sometime after tasseling, but infections that attack plants early can cause early-leaf death and even premature death to the plant. Fungicides with only a protective activity will not cure infections that have already begun. This is why fungicides that combine both preventive and curative active ingredients in one product are so effective. The curative component (propiconazole) will stop existing infections and the preventive component (azoxystrobin) will provide further protection of the crop canopy. Understanding what a fungicide will and will not do is critical in control diseases.

While Minnesota corn growers started the season off well by averting the planting delays seen by much of the Midwest, the cold weather and lack of rain after planting has allowed for some difficult weed control challenges. Lambsquarters has been voted “Weed of the Year,” by retailers and growers who have been battling its presence in fields across the state. Due to a colder than normal spring, the lambsquarters had not yet germinated when growers cultivated their fields, which left thousands of seeds to take root alongside the crop. Growers who chose a post-emergence herbicide that combined glyphosate with residual control found a convenient way to manage the heavy weed pressures.

Using a residual herbicide provides extended control of lambsquarters and other prevalent broadleaf weeds in Minnesota like waterhemp and ragweeds. Now, after a week of above average temperatures and some rain, the corn is rapidly growing toward canopy and growers who used residual herbicides are satisfied with the length of weed control they’ve seen. Conversely, for growers who chose glyphosate alone, which provides no residual control, the heavy weed pressures seen this year may prompt them to rethink their 2010 herbicide plans to achieve season-long weed control.

As the corn crop in Minnesota neared complete canopy,
residual herbicides still held back heavy weed pressure.
Photo taken late June 2009, LaSalle, MN.

At a plot tour in North Carolina, my colleagues heard the same thing we’ve been hearing all across the South…growers are having a heck of a time getting a handle on Palmer pigweed and marestail. Time and again, growers say that glyphosate alone is not keeping their fields clean and they’re doing their best to be proactive about resistance by mixing up their chemistries as much as possible.

Those who’ve been able to catch the weeds before they emerge or when they are still small and vulnerable have had the most success.